What Causes Kidney Pain, Frequent Urination And Vaginal Discharge?

Hello!
I've suffered from UTI/bladder infection symptoms for a while (discomfort, mild kidney pain, frequent urination with very little urine, frequent urge to urinate, etc.) and got tested for a UTI yesterday at my doctor's office. It came back negative, so I'm not sure what's wrong.
Also, when these symptoms are particularly bad, I will feel a wetness just above my anus between my buttocks right after urinating. It's clear, odorless, etc. Mostly just very annoying and rather uncomfortable.
For background, I am not sexually active and don't remember the last time I had a bladder infection.
Any idea what's up? Thanks!